A debate is taking place in California over a proposed maximum contaminant level (MCL) for hexavalent chromium in drinking water. The proposed MCL from the California Department of Public Health (CDPH) is 10 parts per billion (ppb), one fifth of the current MCL of 50 ppb for total chromium.

Everyone agrees that Californians should have safe, affordable drinking water. But what level of hexavalent chromium in water is safe and how much will water treatment cost Californians?

Research on Drinking Water and Hexavalent Chromium

Recent research conducted on hexavalent chromium in drinking water provides strong data that can help regulators determine an MCL that protects human health. Experts in water safety and regulation have recently weighed in on the debate in an op-ed published in California. Peter S. Silva, former Assistant Administrator for the United States Environmental Protection Agency’s Office of Water, and Richard Atwater, Executive Director of the Southern California Water Committee, write that the new research from ToxStrategies supports the current California MCL of 50 ppb:

The findings by the independent company Tox Strategies, in cooperation with numerous universities, indicate that California’s existing standard of 50 parts per billion for total chromium is sufficiently protective. The Tox Strategies studies found that at dosages likely encountered by humans, Chromium 6 converts to Chromium 3 in the human stomach as it oxidizes.

Given the quality of the recent research, which consists of 14 peer-reviewed papers published between 2011 and 2013, many are questioning the need for an MCL of 10 ppb. David Kimbrough, Pasadena Water and Power water quality general manager, said, “The health benefits are overrated.”

Water Utilities Raise Concern over Costs

Numerous water agencies in California have expressed serious concern about the affordability of implementing the proposed MCL. Coachella Valley Water District (CVWD) Director of Environmental Services Steve Bigley wrote in a letter to the California Department of Public Health, “The proposed regulation fails to provide an accurate estimate of the costs of compliance.” Bigley also wrote, “Unfortunately, thousands of households throughout California will not be able to afford the cost.” According to the Desert Sun, “CVWD has estimated costs of about $500 million in the [Coachella] valley, and has warned that its customers could see rates shoot up by as much as $50 a month.”

Californians who are served by smaller water systems may see even higher costs. At a public hearing on the issue last week, Richard Atwater said, “Persons served by very small water systems impacted by chromium-6 should expect their water bills to increase by more than $5,000 per year.”

ACC’s Position

ACC supports regulatory policies that seek to further protect public health, provided that such policies are based on credible scientific information, an economic feasibility evaluation, and viable cost- benefit analyses. As the science shows, the State of California can still protect the health of its residents and limit burdensome costs on businesses and households by maintaining the current MCL of 50 ppb.

CDPH should reissue an MCL that is both health-protective and economically feasible.